Farm Animals

Keel Bone Fractures in Laying Hens

Keel bone fractures affect the majority of laying hens in enriched colony and free-range systems, causing chronic pain that is only recently receiving serious research attention.

Key Facts

Post-mortem studies find keel bone fractures in 50-80% of end-of-lay hens
Fractures occur from collisions with perches, nest boxes, and other equipment
They cause chronic pain evidenced by pain-assessment grimace scale changes
Calcium metabolism during egg production weakens bone density
Aviary systems with modified perch design reduce fracture rates

Welfare Considerations

Keel bone fractures represent the most prevalent welfare problem in laying hens and one that has received insufficient attention relative to its scale. Chronic pain from unhealed fractures may affect hens for months. Genetic selection for bone strength, modified perch design, better lighting to reduce collision risk, and appropriate calcium nutrition are evidence-based interventions that can substantially reduce fracture rates.

What You Can Do

Support research funding into keel bone fracture prevention
Advocate for keel bone assessment as a mandatory welfare outcome indicator
Choose eggs from producers engaged in keel bone reduction programmes
Encourage egg producers to participate in research trials
Support assurance schemes beginning to incorporate bone welfare metrics